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From the decline of anchovy populations to the increase of drought and tropical storms. All of these phenomenon have been linked to El Nino and La Nina events.
Cooler, nutrient rich waters associated with El Nino drop along with the thermocline, driving the anchovy population down with it, or killing off a large portion.
Under normal conditions, warm surface water is pushed away from the coasts of Peru by the trade winds. The relaxed trade winds associated with El Nino in the central and western Pacific leads to a depression of the thermocline (the buffer zone between the upper layer of water and the frigid ocean below) in the eastern Pacific, and an elevation of the thermocline in the west. During La Nina episodes, the equatorial sea surface temperatures (SST) are abnormally cold from the date line eastward to the west coast of South America, and tropical rainfall and convection tends to be focused over the western equatorial Pacific and Indonesia.
Observations of conditions in the tropical Pacific are considered essential for the prediction of short term (a few months to 1 year) climate variations. To provide necessary data, NOAA operates a network of buoys which measure temperature, currents and winds in the equatorial band . These buoys daily transmit data which are available to researchers and forecasters around the world in real time. But what about the rest of the ocean outside the equatorial band? Since oceans cover about 70% of the earth’s surface, our ships, buoys and other in situ (at the collection site) instruments can’t possible cover that much space. Thanks to advanced space technology, we can now use satellites to help us collect large amounts of ocean data.
Satellites have revolutionized the ocean sciences. They have advanced our knowledge about the weather and ocean processes more than any other tool. Instruments on satellites measure wind, waves, temperature of the sea surface, ocean color, ocean surface currents, and tides. Oceanographers can use these satellite measurements for numerical modeling to predict what is happening in the deep ocean.
The TOPEX/Poseidon (T/P) was launched in 1992 and has since mapped the ocean's surface topography. T/P covers the entire planet every 10 days--an impossibility for a ship. Radar altimeters on TOPEX/Poseidon (T/P) accurately measures the satellite's distance from the ocean's surface and tells us about the ocean's surface currents, winds, and wave heights. TOPEX/Poseidon data are used to predict the position of swift currents that appear to be connected with eddies. Eddies are spinning water currents--like a giant whirlpools and are considered to be the "weather of the oceans." Knowing the locations of eddies can increase the safety of workers on oil production platforms and other ocean going vessels. It is helpful in ship routing, commercial fishing, sailing, hurricane prediction, studying ocean circulation, and climate forecasting.
The TOPEX/Poseidon satellite made headlines during the 1997-98 El Nino. Scientists were able to track this El Nino in a way never before possible. The ability to predict the occurrence of El Nino’s and La Nina’s might lessen their impact. It helps warn meteorologists (people who study the weather) about El Nino and La Nina and other weather patterns. Although TOPEX/Poseidon has done an outstanding job, it's time to retire him and let his big brother Jason-1 take over.
The last strong La Nina event occurred in 1988-89. Historically, El Nino and La Nina events have usually alternated with a period of about 2-7 years. However, since the late 1970's El Nino years have outnumbered La Nina years by a factor of about 2 to 1.
What’s a phenomena? An event that impresses one as out of the ordinary; sometimes unexplainable Elementary my dear Watson? Sherlock Holmes
Strange phenomenonoccur during an El Nino and La Nina like...